Several experimental preparations have been used to study the effects of various pharmacological interventions on protein phosphorylation. These include the bullfrog sympathetic ganglion, cholinergic synaptosomes from the squid optic lobe, rat erythrocytes, guinea pig hippocampal slices, and plasma membrane from synaptosomes derived from various regions of rat brain. The pharmacological effects of calcium ion, dantrolene, cyclic nucleotides, ethanol, phosph diestease inhibitors, potassium channel blockers, as well as the direct effects of protein kinase (and its catalytic subunit) have been studied. Specific proteins were phosphorylated in each of these systems under control conditions. In the case of intact bullfrog ganglia P-32-incorporation was calcium-dependent but cyclic nucleotide independent. Increasing intracellular calcium (using the ionophore A23187) caused a decreased phosphorylation, as did KC1 depolarization. Dantrolene caused a twofold increase in phosphorylation. Generally low concentrations of ethanol (less than 50 mM) increased P-32 incorporation into proteins, while high concentrations (greater than 100\mM) decreased incorporation. Theophylline (10 mM) abolished the low concentration effect of ethanol. Protein kinase elevated the protein phosphorylation of ganglia proteins in homogenates as did pyrophosphate, whereas calcium inhibited phosphorylation. In squid optic lobe synatosomes phosphorylation was dramatically stimulated by 4-aminopyrodine. This pharmacological stimulation was calcium dependent. In rat erythrocyte ghost a spectrin-like protein was phosphorylated, and this phosphorylation was increased in alcohol treated rats. Patterns of protein phosphorylation have also been characterized in a variety of mammalian neuronal systems, and th effects of ethanal withdrawal has been studied in rat brain plasma membranes. Certain brain regions (e.g. cortex and hippocampus) showed an increased phosphorylation during alcohol withdrawal, whereas other regions did not (e.g. cerebellum and brain stem). This information provides a biochemical basis for the investigation of altered central nervous system biochemistry associated with alcohol dependence and withdrawal.